Was It Or Wasn't It

A Memory of Bletchley.

There seems to be a lot of controversy about the Shoulder of Mutton, have I got this right? Way way back, the Shoulder of Mutton was built, eventually it was demolished and the old brick house on the other side of the road was converted into a pub. When it first opened, was it called The Three Trees from day one, or was it The Shoulder Of Mutton for a while before they re named It?